PFBC Issues Alert on Didymo found in Pine Creek

After confirming the presence of the invasive aquatic algae known as didymo, or “rock snot,” in Pine Creek, Lycoming County, anglers and boaters are reminded that cleaning their gear is the easiest, most effective means of preventing its spread to other waters.

“Our biologists have not seen any evidence of a full bloom of didymo in the creek or nearby waterways,” Department of Environmental Protection Acting Secretary Chris Abruzzo said. “This algae does not present a public health risk, but there is an ecological concern in terms of its future potential impact on the health of the waterway.”

In late June, DEP biologists were conducting routine stream monitoring in Pine Creek upstream of Waterville in the vicinity of the Hamilton Bottom Canoe Access Area, a popular recreational destination. Laboratory analysis of a sample collected using an algal net detected the presence of didymo in the form of microscopic diatoms, a finding confirmed by the National Academy of Sciences.

The Pennsylvania Fish and Boat Commission (PFBC) continued to urge anglers and boaters to take steps to prevent the spread of the algae.

“We may not be able to eliminate didymo from an infected waterway, but there are easy steps we can take to slow its spread and to prevent it from spreading to other waters,” said PFBC Executive Director John Arway.

“Didymo cells can easily be carried downstream and can be picked up by any items which come in contact with the infected water, including fishing tackle, waders, and boats and trailers. We urge anglers and boaters to ‘Clean Your Gear!’ before leaving a water body and entering another one.”

The discovery of the algae in a popular recreational area potentially increases the risk of its movement to other waters in Pennsylvania.

“Flowing through the heart of Tiadaghton State Forest, Pine Creek and its parallel trail are increasingly popular with anglers, boaters, hikers and other Pennsylvania residents and visitors,” said Department of Conservation and Natural Resources Acting Secretary Ellen Ferretti.

“The discovery of didymo has no immediate impact to the visitor experience on or along Pine Creek, but we ask all to remain vigilant in an effort to protect this invaluable waterway and other streams and rivers,” Ferretti said.

Prior to detecting didymo in Pine Creek, the alga was found in the Youghiogheny River watershed in Fayette County, in the West Branch and main stem of the Delaware River, and in Dyberry Creek in Wayne County.

The PFBC recommends that anglers allow exposed equipment to completely dry before entering new waters. After equipment is dry to the touch, allow it to dry another 48 hours, the commission suggests. Thick and dense material, such as life jackets and felt-soled wading gear, will hold moisture longer, take longer to dry, and can be more difficult to clean.

Soaking equipment in hot water containing dishwashing detergent (two cups of detergent for every two and a half gallons of water) for 20 minutes or more also will kill didymo and some other aquatic invasive species.

Cleaning boats and equipment with hot water (maintained at 140 degrees Fahrenheit) by pressure washing or soaking is another effective method. If hot water is not available, a commercial hot water car wash also makes a good location to wash boats, motors and trailers. At the other end of the temperature range, freezing items solid for at least 24 hours is effective. If cleaning, drying or freezing is not practical, please restrict the equipment’s use to a single waterway.

Didymo is not a public health hazard, but it can cause ecological damage by smothering other organisms which also live on the riverbed and support the food web for the resident fish community.

The algae, whose scientific name is “Didymosphenia geminata,” has colloquially been called “rock snot” because of its appearance. When squeezed nearly dry, the algae, generally tan to beige in color, actually has the feel of moist cotton or wool.